At least 250 pupils have also been reported to the National Assessment Agency for alleged cheating. And 58 schools were under investigation after two sets of handwriting were detected on pupils' papers.
The findings come from an official report on test "maladministration". As The TES revealed in May, there has been a more-than-four-fold increase in the total number of cases of cheating reported to the agency since 2000.
The figures come amid claims that test cheating is widespread, but the agency says the number of cases reported to it is small. Some 248 teachers were investigated for "over-aidingcoaching" pupils between 2002 and 2005 in key stage 1, 2 and 3 tests; 251 pupils were reported for cheating during the tests in these years.
At least 27 children were reported for causing disruption, while in 51 schools an "over active amanuensis or reader" precipitated an investigation. Other offences reported included seemingly minor rule infringements - from "inappropriate storage of test materials" to "printing faults on papers and packing issues".
Some schools appear to have allowed pupils to use calculators during mental arithmetic papers.
It seems that the agency took action against the schools concerned in very few cases. The number of schools in which an entire year group had its results annulled for a subject has averaged five a year since 2001 after peaking in 1998 when 38 schools were penalised.
Last year, the number was six; 240 out of 600 cases of alleged maladministration in 2005 were reported by schools themselves.They have been warned to look for staff or pupils flouting the rules.
Most of the rest were reported by markers and local authorities. Since 2004, they have been issued with extra guidance on whistle-blowing .
The report said: "There were a very few isolated cases of teachers 'overstepping the mark' in terms of aiding their children, with tragic consequences for their careers and the pupils' results."
Teachers found guilty of cheating face being reported to the General Teaching Council or even being sent to prison. In 2003, Alan Mercer, head of South Borough primary in Maidstone, Kent, was jailed for three months after altering answers on KS2 tests and grammar school entry exams.
In June, Henry Walpole, The TES's primary blogger, suggested that test cheating is widespread.
He wrote: "Although nobody ever admits to cheating, every teacher will tell you they know a school where they 'do that type of thing'.
"Cheating can take many forms and can range from the simple cough by an invigilating teacher to alert a pupil they have got a question wrong to teachers miming the answer to a particularly difficult science question."
The agency passed the report, "Managing allegations of maladministration"
to ministers in March. But it was only released after The TES used the Freedom of Information Act to obtain it.
* Ioannis Markopoulos, who taught at King Edmund school in Essex, has been banned from overseeing and moderating GCSE exam coursework for two years.
England's General Teaching Council found him guilty of unacceptable professional conduct after he changed a pupil's name on GCSE coursework. An entire class had to re-do all pieces of their maths coursework.
Mr Markopoulos is now working as a maths teacher at Prittlewell technology college, Essex.